Conventional thermal inkjet printers are provided with a plurality of printheads for firing drops of ink. A sufficient amount of energy must be applied to the printheads to properly fire the drops of ink. If the applied energy is too low, there may not be enough energy to drive the printhead to eject ink drop, or the velocity of the drop may be too low, thereby resulting in defects in the printed image. If the applied energy is too high, the printheads may get too hot resulting in decreased pen life. For these reasons, accurate energy control is essential for proper operation of the printheads. Typically, a switching voltage regulator is used to supply the desired electrical energy to the printheads. The voltage regulator is configured to receive direct current electrical energy from a power supply source and convert the direct current voltage to a regulated output voltage for use by the printheads. Conventional voltage regulators include step-down Buck controllers and other power components that increase the size and cost of the printers. It generally requires a more complex power supply system to drive the printheads. Therefore, there remains a need for a simple power voltage regulator that can be implemented at a low cost and can be installed in a smaller sized printer.